issue with 460v hvac system

I don’t work on a lot of 460v equipment, but I was working on this system that had a blown fractional fuse on the line side of a 460 primary to a 240 sec xfmr, I replaced fuse and blew again. I checked circuit to ground and across and got nothing. I then checked voltage coming in and it was 500v. I then bypassed the fuse and tested, I got 2 amps being pulled by transformer which goes to a stepdown transformer 240 to 24v. I was getting 270 on the sec side of the first transformer, and 31v at the stepdown secondary. My question is, would the higher then normal voltage being supplied to the unit be the cause of the high voltage across all transformers and blow the fuse.

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